Abstract：The present paper reports the study of the effects of temperature on the absorption cross-sections of ammonia in spectral region of 200-220 nm. By using a grating monochromator with high resolution, deuterium lamp, closed gas sample cell and gas compounding device, the photoabsorption cross sections of ammonia were measured at temperatures ranging from 308 to 397 K. The absorption spectrum of NH3 consists of discrete bands superimposed on a continuous base. Results indicated that the cross sections at the peaks of the discrete bands decreased with the increase in temperature, which corresponded to the decrease in the population of vibrational and rotational transitions from the base level to higher excitation levels. The absorption cross section peaks decreased when the temperature increased from 308 to 397 K, with a relative drop of 46%. Another distinctive feature of ammonia absorption spectra in the above spectral regions was the quasiperiodic structure of absorption peaks, whose equal wavelength interval was 4 nm. Besides, absorption peak positions were not changed. Continuous absorption cross section decreased with the increase in temperature, and the variation gradient gradually decreased with wavelength red shift. A compensation calculation for temperature should be carried out in on-line measurement of concentration because of the greater variation rate of absorption cross sections of ammonia.
周洁,龙志云,赵翠. 温度对NH3气体紫外吸收截面影响研究[J]. 光谱学与光谱分析, 2009, 29(04): 982-985.
ZHOU Jie,LONG Zhi-yun,ZHAO Cui. Study on Temperature Dependence of Ultraviolet Absorption Cross Sections of Ammonia. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2009, 29(04): 982-985.
[1] SUN Xiu-yun, LI Yan, WANG Jun-de(孙秀云，李 燕，王俊德). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2003, 23(4): 739. [2] MA Wei-guang, YIN Wang-bao, HUANG Tao，et al(马维光，尹王保，黄 涛，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2004, 24(2): 135. [3] Johan Mellqvist，Arne Rosén. Journal of Quantitative Spectroscopy and Radiative Transfer, 1996, 56(2): 187. [4] WU Zhen(吴 桢). Theoretical and Experimental Studies of Differential Optical Absorption Spectroscopy on Atmospheric Trace Gases(大气痕量气体监测的差分吸收光谱技术理论与应用研究). Tianjin: Tianjin University Press(天津：天津大学出版社)，2003. [5] WU Zhen, YU Qi-lian, ZHANG Fan, et al(吴 祯，虞启琏，张 帆，等). Journal of Scientific Instrument(仪器仪表学报)，2004, 25：470. [6] ZHOU Jie, ZHANG Shi-liang, CHEN Xiao-hu(周 洁，张时良，陈晓虎). Spectroscopy and Spectral Analysis(光谱学与光谱分析)，2007, 27(7): 1259. [7] ZHANG Shi-liang, ZHOU Jie, CHEN Xiao-hu(张时良，周 洁，陈晓虎). Journal of Zhejiang University: Engineering Science(浙江大学学报·工学版)，2007, 41(2): 329. [8] Johannes Orphal，Kelly Chance. Journal of Quantitative Spectroscopy and Radiative Transfer, 2003, 82: 495. [9] Prahlad V, Ahmed S M, Kumar V. Journal of Quantitative Spectroscopy and Radiative Transfer, 1996, 56(1): 57. [10] Prahlad V, Kumar V. Journal of Quantitative Spectroscopy and Radiative Transfer, 1997, 57(5): 719. [11] Stanley L M, Arthur L L. Journal of Quantitative Spectroscopy and Radiative Transfer, 1993, 50(3): 267.
